Fort Donelson

Fighting at Fort Donelson raged from February 11 to 16, 1862, as part of the war's Western Theater. When Union forces seized this Confederate stronghold near where Tennessee meets Kentucky, they gained control of the Cumberland River, a vital corridor for pushing deeper into Southern territory. This victory transformed Brig. Gen. Ulysses S. Grant from a relatively unknown and untested commander into a major general, and gave rise to his famous moniker, "Unconditional Surrender" Grant.

After seizing Fort Henry on February 6, Grant marched his troops, who would eventually form the Army of the Tennessee, twelve miles overland toward Fort Donelson between February 11 and 13, launching a handful of minor probing assaults along the way. Then on February 14, Flag Officer Andrew H. Foote led Union gunboats in an effort to pound the fort into submission, but the vessels sustained serious damage from the fort's water batteries and had to pull back.

By February 15, Confederate forces found themselves encircled, prompting commander Brig. Gen. John B. Floyd to order a surprise assault on the right flank of Grant's army. Brig. Gen. Gideon Johnson Pillow, serving as second-in-command, led this attack, which aimed to carve out an escape corridor toward Nashville, Tennessee. Grant had been absent from the field when the assault began, but he returned in time to rally his troops and mount a counterattack. Although Pillow managed to break open the escape route, Floyd's resolve faltered and he pulled his men back into the fort. Come morning, both Floyd and Pillow fled with a small group of soldiers, handing command over to Brig. Gen. Simon Bolivar Buckner, who that evening agreed to Grant's terms of unconditional surrender. In the aftermath, nearly the entire state of Kentucky and a substantial portion of Tennessee, Nashville included, fell under Union authority.

Background

Fighting at Fort Donelson erupted on February 12, coming close on the heels of the fall of Fort Henry, Tennessee, which had surrendered on February 6, 1862. That earlier fort had guarded a crucial midpoint in the line protecting Tennessee, so once it fell, Union forces gained free passage along the Tennessee River for troops and supplies. Roughly 2,500 Confederate soldiers stationed there managed to slip away before the surrender, covering the twelve miles east to reach Fort Donelson on foot. Union troops then severed the rail lines south of the captured fort in the days that followed, which limited how easily Confederate reinforcements could shift laterally to counter the larger Federal force bearing down on them.

The loss of Fort Henry left Confederate leadership with few good options. Grant's army now sat between the two principal wings of Gen. Albert Sidney Johnston's command: Major General Leonidas Polk's 12,000 men at Columbus, Kentucky, and William J. Hardee's 14,000 at Bowling Green. Only about 5,000 troops held Fort Donelson itself, though Floyd and Buckner were in the process of shifting 8,000 men from Russellville, Kentucky, toward Clarksville, Tennessee. From the Union perspective, several courses seemed possible: a strike on Columbus, an assault on Fort Donelson that would put Nashville at risk, or a combined push against Johnston by Grant and Maj. Gen. Don Carlos Buell, whose 45,000 troops were based in Louisville, with Grant trailing Buell's advance. To weigh these possibilities, Johnston met with his deputy, General Pierre G.T. Beauregard, and with Hardee, gathering at Beauregard's Bowling Green headquarters, Covington House, on February 7. All three worried over how quickly the Union gunboats had overwhelmed Fort Henry, not realizing that rising floodwaters on the Tennessee River had done much of the work by swamping the fort. Concluding that Donelson could not be held, they settled on a plan that essentially surrendered the initiative across nearly the whole Confederate line in Tennessee, a decision that quietly conceded their defensive strategy had failed.

Under this plan, Columbus would be abandoned and its garrison sent south, the army at Bowling Green would pull back to Nashville, and Floyd's men would take charge of guarding the Cumberland River. Johnston's preference was to hand this district command to Beauregard, whose performance at Bull Run had impressed him, but a throat ailment led Beauregard to decline. The duty fell instead to Floyd, freshly arrived after a failed stint serving under Robert E. Lee in western Virginia. Floyd carried political baggage as well: authorities in the North wanted him on charges of graft and secessionist dealings dating from his time as Secretary of War under James Buchanan. Though his career had been built in politics rather than the military, his rank as senior brigadier general on the Cumberland gave him the post regardless.

Across the lines, Grant's commanding officer in the Department of the Missouri, Maj. Gen. Henry W. Halleck, harbored his own doubts. He had cleared Grant to move against Fort Henry, but now worried that pressing on toward Donelson courted disaster. Grant's string of successes did little to reassure him, since Halleck viewed his subordinate as impulsive. He even tried persuading his rival Buell to assume control of the campaign so that Buell's extra manpower could be brought to bear. Johnston thought highly of Buell, yet the Union general proved just as cautious as Grant was bold. Grant himself had no idea his superiors were weighing his removal, though he understood that any setback or delay might give Halleck the excuse he needed to lose confidence and call off the entire operation.

On February 6, Grant sent word to Halleck that Fort Henry had fallen and promised to seize and destroy Fort Donelson by the 8th before returning to Fort Henry. That timeline proved far too ambitious, undone by three problems: the wretched state of the twelve-mile road to Donelson, the necessity of hauling supplies clear of the rising floodwaters that would leave Fort Henry entirely submerged by February 8, and the battering that Foote's Western Gunboat Flotilla had taken in its artillery exchange with Fort Henry. Had circumstances

Surrender (February 16)

By day's end nearly 1,000 men from both armies lay dead, and roughly 3,000 more remained wounded on the field. A snowstorm claimed additional lives, as numerous Union soldiers had discarded their blankets and coats and froze where they lay.

Strangely, Floyd and Pillow felt confident about how the fighting had gone and sent word to Johnston in Nashville proclaiming a great victory.

Aftermath

The scale of bloodshed at Fort Donelson stemmed largely from the massive number of Confederates who surrendered. On the Union side, 2,691 men fell as casualties: 507 dead, 1,976 wounded, and 208 taken prisoner or missing. Confederate losses dwarfed this figure at 13,846, comprising 327 killed, 1,127 wounded, and a staggering 12,392 captured or unaccounted for.

News of the victory set off celebrations across Northern cities, with cannon fire and pealing church bells marking the occasion. The Chicago Tribune captured the mood, declaring that the city had "reeled mad with joy." This triumph, paired with the earlier fall of Fort Henry, represented the war's first major Union successes and threw open two vital rivers for further advances into the Southern heartland. In recognition, Grant received promotion to major general of volunteers, ranking beneath only Henry W. Halleck among Union commanders in the western theater. Word spread through newspapers that Grant had secured victory while gripping a cigar between his teeth, and soon admirers flooded him with so many cigars that he could not possibly give them all away. Though he had smoked only occasionally before this, he began indulging regularly, a habit that likely played a role in the throat cancer that eventually killed him. In his later memoirs, Grant reflected that consolidating all Union forces in the west under one commander at that moment could have brought the war in that region to a swift conclusion.

Nearly one third of Albert Sidney Johnston's entire army now sat in Union custody. No American general before Grant had ever taken so many prisoners in a single engagement, and Johnston found himself short more than twelve thousand troops, soldiers who might have tipped the balance decisively when the armies clashed again at Shiloh less than two months later. What remained of Johnston's forces sat scattered across 200 miles, divided between Nashville and Columbus, with Grant's army positioned squarely between the two. Grant's troops also held sway over the surrounding rivers and rail lines. Meanwhile, Buell's forces bore down on Nashville and Pope's men pressed toward Columbus. Johnston abandoned Nashville on February 23, handing the Union its first captured Confederate state capital and surrendering a key industrial hub in the process. Columbus followed on March 2, falling under Union control as well. By this point, nearly the whole of Tennessee, along with the entirety of Kentucky, had come under Union dominance, though both states would continue to face the threat of invasion and sporadic Confederate raids.